Desired properties of galvanically isolated integrated circuit (IC) magnetic field current sensors include high magnetic sensitivity; high mechanical stability and reliability; low stress influence to Hall sensor elements near chip borders; high thermal uniformity and low thermal gradients; high isolation voltage; minimized electromigration issues; and low manufacturing costs. Conventional current sensors can include one or more features or be manufactured in ways that aim to address these desired properties.
For example, some current sensors use the leadframe as a current lead. Others also include a magnetic core. Such sensors, however, can be expensive to manufacture.
Other current sensors include additional layers, such as special magnetic layers on top of the silicon die or a thick metal layer formed on the isolation layer. These sensors are also expensive, and the former can be sensitive to disturbance fields and can suffer from drawbacks related to the positioning of the current leading wire outside of the IC.
Therefore, there is a need for a galvanically isolated IC magnetic field current sensor having desired properties while minimizing drawbacks.